阅读下列短文，从每题所给的四个选项（A，B，C和D）中，选出最佳选项。
A
For almost forty years the Empire State Building in New York City was the world's tallest skyscraper（摩天大楼）. The building reaches a height of 1, 250 feet. It has 102 floors. The use of steel frames made its height possible. Steel walls can rise height without needing to be thick. Steel frame construction is strong. All plates are fixed firmly together by metal bolts（螺栓）called rivets （铆钉）. When set in place, rivets are usuall red- hot. One end is already rounded. A riveter uses a special hammer to shape the other
